Effects of adjunct treatment with intravenous immunoglobulins on the course of severe COVID-19: results from a retrospective cohort study.

Objectives: To evaluate the effect of adjunct treatment with Octagam, an intravenous immunoglobulin (IVIG) product, on clinical outcomes and biomarkers in critically ill COVID-19 patients.

Methods: Data from a single center was analyzed retrospectively. Patients had received preliminary standard intensive care (SIC) according to a local treatment algorithm, either alone or along with IVIG 5% at 30 g/day for 5 days. The two groups were compared regarding baseline characteristics, survival and changes in inflammation markers. Imbalance in baseline APACHE II scores was addressed by propensity score matching. Otherwise, Kaplan-Meier and multiple logistic regression models were used.

Results: Out of 93 patients, 51 had received IVIG and 42 had not. About 75% of patients were male and both groups had comparable body mass index and AB0 blood type distribution. IVIG-treated patients were younger (mean 65 ± 15 versus 71 ± 15 years,  = .066) and had slightly lower baseline disease scores (APACHE II: 20.6 versus 22.4,  = .281; SOFA: 5.0 versus 7.0,  = .006). Overall survival was 61% in the SIC + IVIG and 38% in the SIC only group (odds ratio: 2.2, 95% confidence interval: 0.9-5.4,  = .091 after controlling for baseline imbalances). IVIG significantly prolonged median survival time (68 versus 18 days,  = .014) and significantly reduced plasma levels of C-reactive protein (median change from baseline -71.5 versus -0.3 mg/L,  = .049).

Conclusion: Clinically relevant benefits through adjunct IVIG treatment in COVID-19 need to be confirmed in a randomized, controlled trial.